Insurers Denied 12-18% of Prior Authorization Requests in 2025, KFF Analysis Reveals

In 2025, insurers denied a significant portion of prior authorization requests, with Medicare Advantage insurers denying 12% of standard requests, Medicaid managed care insurers denying 14%, and ACA Marketplace insurers denying 18%. These figures come from a comprehensive analysis by the Kaiser Family Foundation (KFF), which examined data from 14 insurers covering approximately 71 million enrollees.

The KFF report follows a 2024 CMS final rule requiring payers to publicly post prior authorization metrics, including approval and denial rates, on their websites. However, the data does not specify which types of services are most often denied, leaving gaps in transparency for consumers.

For patients, prior authorization is a crucial step that can determine whether they receive necessary treatments or medications. Denial rates vary widely by insurer, with some plans denying as few as 5% of requests and others rejecting up to 25%. This variability highlights the inconsistent application of prior authorization policies across different health plans.

Understanding Prior Authorization Denials

The KFF analysis also revealed that the median response time for standard prior authorization requests was about one day. For expedited requests, which are typically needed when a patient's condition is urgent, the median response time was about half a day for Medicare Advantage and approximately one day for Medicaid managed care and ACA Marketplace plans. Interestingly, denial rates for expedited requests were slightly lower than for standard requests.

Despite these denials, patients rarely appeal them. When they do, however, many appeals are successful. In Medicare Advantage, about 67% of prior authorization denials were overturned after an appeal, compared to 47% in Medicaid managed care and 43% in ACA federally facilitated Marketplace plans. This suggests that insurers may be overly cautious or inconsistent in their initial decisions.

Denial rates also vary significantly by insurer. For Medicare Advantage, Elevance had the lowest denial rate at 5%, while UnitedHealth Group had the highest at 17%. In Medicaid managed care, L.A. Care Health Plan had the lowest rate at 2%, and Independence Health Group had the highest at 23%. Among ACA Marketplace insurers, GuideWell had the lowest denial rate at 3%, and Centene had the highest at 25%.

Why It Matters

The high denial rates for prior authorization requests have significant implications for patient care and access to treatments. Prior authorization can delay necessary medical services, leading to potential health complications or worsening conditions. For example, a denied request for a cancer treatment could mean a critical delay in starting therapy.

While the 2024 CMS rule aimed to increase transparency by requiring insurers to publish prior authorization metrics, there are still significant gaps. Insurers are not required to use a standard format for publishing this data, making it difficult for consumers to compare plans effectively. This lack of standardization can leave patients and healthcare providers in the dark about which services are most likely to be denied.

To address these issues, policymakers and advocates are calling for more robust regulations and standardized reporting requirements. Ensuring that prior authorization processes are fair, transparent, and consistent could help improve patient outcomes and reduce unnecessary delays in care.

For now, patients and healthcare providers must navigate a complex and often opaque system of prior authorizations. As the data from KFF highlights, there is a need for ongoing monitoring and reform to ensure that prior authorization serves its intended purpose of improving patient care rather than creating barriers to essential treatments.